Measuring the Color of Clear Liquids

Liquid Fragrance Sample

Liquid Fragrance Sample

One application that often comes up is measuring the color of clean liquids such as the fragrance sample seen above. This liquid fragrances is clear and looks almost like water. Fragrances such as this are often added to cleaning supplies, air fresheners, or other consumer products. One of the problems that this type of sample can experience is that the chemistry of the liquid fragrance solution can go bad and it will start to visually yellow. This is a concern of the manufacture because if the liquid fragrance yellows it cannot be added to the end product. Continue reading

Do you have a source for liquid Saybolt and ASTM D1500 Color Standards?

These liquid visual color standards can be used as an independent test to verify instrumental Saybolt and ASTM D1500 Color measurement performance over time for these two visual color scales used to evaluate oil, oil additive and petrochemical color quality.

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How do you measure the color of bare metal materials?

Bare Metal Brass Disks

Bare metal with a brightened, polished surface showing both color and gloss characteristics in the specular reflectance with a rapid fall-off to near black at the aspecular angles.

Bare metals are classified as opaque metals and do not allow any light to pass through them. In opaque metals, the specular reflection and diffuse reflection are key to defining the light interaction of this unique sample type. For bare metals both color and gloss are seen in the specular reflection which makes up a large portion of the reflection. Continue reading

When do I use Specular Exclusion in Color Measurement?

FAQ: ASTM D6290 recommends that I measure my plastic pellets for yellowness using the specular exclude mode. What is this?

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How is polarization minimized in HunterLab sphere instruments?

FAQ: “Do you sell a depolarizer for my HunterLab sphere instrument?  On occasion we test polarized samples and there is definitely a dependence on the orientation of the lens.  I was wondering if adding a depolarizer would eliminate this phenomenon?”

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What tolerance should be used for a PQ Performance Qualification on Transmission Color Measurements?

FAQ: “What is the limit on the standardization in TTRAN.  Using the small sample flask, filled with Ultra pure water. If they follow the protocol, they expect to find values (CieLab: 100.0; 0.0; 0.0)?” Continue reading